Yamaha DTXpress/DTXplorer/DTXtreme

i was a little bit dissapointed. i've played the set for a few 
minutes in a music store. i was doing fast double strokes (+ ghost 
notes) on the snare pad, but the thing couldn't keep up, there were 
quite a few missing notes. same story with the kick pad (it missed 
few notes). is this common? what's the situation with drumpad's 
sensitivity? 

ok first of all i'm a begginer at e-drums and i don't now anything 
about module/pad settings. can this be fixed? is it possible that the 
dtxpress set (from store) was thrashed from customer abuse or wasn't 
properly set? i need e-drums for silent practise/playing at home, 
nothing else (don't have the money for dtxtreme :) and i wouldn't 
like to experience this at home, spending 1000$ and regret it...

but i'm glad that u guys are satisfied with dtxpress, so after all 
it's a good product?